V-Belt Power Rating Calculator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Mechanical, Civil & Structural Engineering — Statics/Dynamics, Strength of Materials, Machine Design, Civil, HVAC, Vibration

Tranche

tranche-7

Evidence ID

t7-042

Ledger rows

1

No ledger note is attached.

Review findings

The core arithmetic is standard, but the specification is not sufficiently precise for a universal calculator. Require a named belt manufacturer/catalog, belt section, speed, small-sheave diameter, belt length convention, and explicit multiplication of all correction factors before treating the result as final.

Formula and scope findings

• The design-power formula is standard: design power = transmitted power × service factor, provided both powers use the same units.
• The belt-count formula is incomplete or ambiguous: arc-of-contact and length correction factors should normally be multiplied together, giving N = design power / (belt rating × arc factor × length factor). The specification does not explicitly state whether 'arc/length correction' means a product, quotient, or one combined factor.
• The required belt count must be rounded up to the next whole belt; the stated division alone can produce a fractional belt count.
• Belt rating is not a universal fixed value: it depends on belt section, belt construction, speed, small-sheave diameter, wrap angle, service conditions, and manufacturer data. A manufacturer-specific rating table is required for a defensible result.
• The formula omits any explicitly required small-sheave-diameter, speed, temperature, center-distance, or belt-matching constraints that may be part of the applicable manufacturer rating method.

Unit assumptions

• Transmitted power and belt rating are both expressed in kW. If one is in hp, use 1 hp = 0.7457 kW before calculation.
• Service factor and correction factors are dimensionless.
• The correction factors are applied multiplicatively: effective power per belt = belt rating × arc correction × length correction.
• Belts required is a nonnegative integer obtained by ceiling the calculated real-valued belt count.
• The reference values below use a generic illustrative lookup convention labeled 'widely tabulated standard value'; actual final sizing must use one identified manufacturer's catalog and belt series.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The zero correction-factor input produces a division-by-zero undefined result, and the exact-zero power boundary produces a mathematically valid zero-belt result that must be rejected as physically invalid. The specification also leaves the power-sign convention and the integer belt-count branch implicit.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "transmitted_power_kW": 10,
    "service_factor": 1.2,
    "belt_rating_kW_per_belt": 5,
    "wrap_angle_deg": 180,
    "belt_length_mm": 1000
  },
  "expected_outputs": {
    "design_power_kW": 12,
    "uncorrected_belt_count": 2.4,
    "belts_required": 3
  },
  "reference_data": {
    "arc_correction": {
      "wrap_angle_deg": 180,
      "factor": 1,
      "source_convention": "widely tabulated standard value"
    },
    "length_correction": {
      "belt_length_mm": 1000,
      "factor": 1,
      "source_convention": "widely tabulated standard value"
    },
    "belt_rating": {
      "rating_kW_per_belt": 5,
      "source_convention": "widely tabulated standard value"
    }
  },
  "working": "Design power = 10.0 kW × 1.2 = 12.0 kW. Effective rating per belt = 5.0 × 1.0 × 1.0 = 5.0 kW/belt. Real belt count = 12.0 ÷ 5.0 = 2.4 belts. Round up: ceil(2.4) = 3 belts. The 180° wrap and 1.00 length factor are exact table entries."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche7/tranche7-results.json
• BOUNDARY_HAZARD_CATALOG.json